1. Field of the Invention
The present invention generally relates to a semiconductor device and a manufacturing method thereof; and especially relates to a semiconductor device, the mechanical strength of which semiconductor device is raised by a stiffener, and a manufacturing method thereof.
2. Description of the Related Art
In recent years and continuing, a semiconductor device wherein a semiconductor chip is mounted on an insulation film is offered. Although this type of semiconductor device has an advantage, in view of such as minute wiring and low mounting profile, there is a problem in that warpage of the semiconductor device occurs after mounting because the insulation film serves as a substrate. For this reason, a stiffener (a member for reinforcement) is arranged on the substrate such that the rigidity of the substrate is enhanced and the warpage is reduced (Patent Reference 1).
FIG. 1 shows a semiconductor device 1A (the first conventional semiconductor device). The semiconductor device 1A includes a substrate 2, a semiconductor element 3, and stiffeners 4. The substrate 2 is a thin substrate consisting of an insulation film, and the thickness is about 0.7 mm. A circuit pattern (not illustrated) is arranged on the substrate 2. The semiconductor element 3 is flip-chip bonded to a central part of the substrate 2. Although not illustrated, external connection terminals, such as solder balls, are prepared on the back side of the substrate 2 (the back side is the side opposite to the side where the semiconductor element 3 is mounted).
If the semiconductor element 3 is arranged at the central part of the substrate 2 without the stiffeners 4, a big warpage will occur in the substrate 2 when the semiconductor element 3 is flip-chip bonded, and when the semiconductor device 1A is mounted to an electronic instrument. For this reason, the stiffeners 4 are arranged in positions that surround the semiconductor element 3 on the substrate 2. The stiffeners 4 are made of metal material having rigidity greater than the substrate 2. By arranging the stiffeners 4 in this way, the substrate 2 is reinforced by the stiffeners 4, and the warpage is reduced.
FIG. 2 shows a semiconductor device 1B (the second conventional semiconductor device) that includes reinforcement resin members 5 in addition to the stiffeners 4. According to the semiconductor device 1A as shown in FIG. 1, there are spaces between the semiconductor element 3 and the stiffeners 4. For this reason, there is a possibility that warpage may occur between the semiconductor element 3 and the stiffeners 4 on the substrate 2.
Then, according to the semiconductor device 1B shown in FIG. 2, the reinforcement resin members 5 are provided between the semiconductor element 3 and the stiffeners 4 for reinforcing the substrate 2. In this way, the magnitude of warpage of the semiconductor device 1B can be made smaller than the semiconductor device 1A shown in FIG. 1.
[Patent Reference 1] JPA 2000-133741